The present invention relates to the art of color proofing, and in particular, to a method of reversing an image when forming a pre-press proof, such as by the use of pressure and heat to laminate media together.
Pre-press proofing is a procedure that is used primarily by the printing industry for creating representative images of printed material. In the printing industry pre-press color proofs are used to check for color balance, control parameters and other important image quality requirements, without the cost and time that is required to actually produce printing plates, set up a printing press and produce an example of a representative image, which would result in higher costs and a loss of profits that would ultimately be passed on to the customer.
To create a pre-press proof first an original image is separated into individual color separations or digital files. The original image is scanned and separated into the three subtractive primaries and black. Typically a color scanner is used to create the color separations or digital files and in some instances, more than four color separations or digital files are used. Although there are several ways used in the printing industry to create a pre-press proof from the color separations or digital files they are generally one of three types. The first method being a color overlay system that employs the representative image on a separate base for each color, which are then overlaid to create a pre-press proof The second, a single integral sheet process in which the separate colors for the representative image is transferred one at a time by lamination onto a single base. The third, a digital method in which the representative image is produced directly onto a receiver stock, or onto an intermediate sheet then transferred by lamination onto a receiver stock from digital files.
The representative image to be laminated can be created on, but is not limited to, a commercially available Kodak image processing apparatus, depicted in commonly assigned U.S. Pat. No. 5,268,708, which describes an image processing apparatus having half-tone color imaging capabilities. The above-mentioned image processing apparatus is arranged to form a representative image onto a sheet of thermal print media in which colorant from a sheet of colorant donor material is transferred to the thermal print media, by applying a sufficient amount of thermal energy to the colorant donor sheet material to form the representative image. The image processing apparatus is comprised generally of a material supply assembly and a lathe bed scanning subsystem. The scanning subsystem includes: a lathe bed scanning frame, translation drive, translation stage member, printhead, imaging drum, and media exit transports.
The operation of the image processing apparatus includes metering a length of the thermal print media (in roll form) from the material supply assembly. The thermal print media is then measured and cut into sheet form of the required length and transported to the imaging drum, registered, wrapped around, and secured onto the imaging drum. Next, a length of colorant donor material (in roll form) is also metered out of the material supply assembly, then measured and cut into sheet form of the required length. The colorant donor material is then transported to the imaging drum and wrapped around the imaging drum utilizing a load roller which is described in detail, in commonly assigned U.S. Pat. No. 5,268,708, such that it is superposed in the desired registration with respect to the thermal print media (which has already been secured to the imaging drum).
After the colorant donor sheet material is secured to the periphery of the imaging drum the scanning subsystem or write engine provides the imaging function. This image function is accomplished by retaining the thermal print media and the colorant donor sheet material on the imaging drum while it is rotated past the printhead. The translation drive traverses the printhead and translation stage member axially along the axis of the imaging drum, in coordinated motion with the rotating imaging drum. These movements combine to produce the representative image on the thermal print media.
Once the representative image has been formed on the thermal print media, the colorant donor sheet material is then removed from the imaging drum. This is accomplished without disturbing the thermal print media that is beneath it. The colorant donor sheet material is then transported out of the image processing apparatus by means of the material exit transport. Additional colorant donor sheet materials featuring other desired colorants are sequentially superimposed with the thermal print media on the imaging drum and then imaged onto the thermal print media as previously mentioned, until the representative image is completed on the thermal print media. The representative image formed thereon is then unloaded from the imaging drum and transported by the receiver sheet material exit transport to an exit tray in the exterior of the image processing apparatus.
After a representative image has been formed on the thermal print media as previously described it is transferred to a receiver stock such that the pre-press proof is representative of the image that will be printed by the printing press. A Kodak laminator as described in U.S. Pat. No. 5,478,434 can be used to bond or laminate the representative image as a part of a pre-press proofing system. As additional references U.S. Pat. No. 5,203,942 describes a Kodak laminator that employs a lamination/de-lamination system as applied to a drum laminator and pending U.S. patent application Ser. No. 09/676,877, filed Sep. 29, 2000, describes a Kodak laminator that employs endless belts incorporated into the lamination apparatus. For the purpose of this patent application the laminator described in U.S. patent application Ser. No. 09/676,877 will be used. It should be noted that the present invention described in this disclosure is not limited to a Kodak laminator or type of laminator referenced above.
The receiver stock can be sheet-fed press printing stock, specially coated paper stock, or previously laminated stock. In this latter case a sheet of pre-laminate, which has a pre-laminate support layer consisting of a suitable base material, optionally coated with a releasing material, and a thermal print layer, is placed on top of a receiver sheet, which is also called receiver stock in the industry. This construction of multiple layers is a lamination sandwich, which is fed into the laminator. Once the lamination sandwich exits the laminator the pre-laminate support layer is peeled away from the now pre-laminated receiver stock. Any of the laminators referred to above can be used to affect the transfer of the pre-laminate receiving layer to the receiver stock.
The above described lamination method works well with both laser thermal and inkjet pre-press proofs, once an original image is scanned and separated into color separations or digital files. If, when printed to a receiver sheet, it is not oriented correctly, or written inreverse in the case of a transferable receiver, the image laminated to paper will be reversed thus rendering the imaged receiver sheet unusable adding cost and loss of profits. Thus, there exists a need to be able to salvage an image receiver sheet having an incorrect orientation.
The present invention provides a method of correcting an imaged receiver sheet having an incorrect orientation created by a pre-press proof on the plastic materials. The novel methods are preferably for forming a pre-press proof with a resolution of about 1000 and about 4000 dpi and most preferably having a resolution of about 1800 to 3000 dpi.
Specifically the invention is for a method of lamination of a pre-press proof, whereby an imaged receiver sheet with an image having been written with an incorrect orientation can be salvaged, which comprises the steps of laminating a pre-laminate sheet consisting of a first thermoplastic layer, first support layer having a first support base, and a first release layer. The first support layer may be comprised of several layers or a single support base laminated to a sheet of paper that the representative image would be printed on in the printing press to be known as receiver stock. The first support layer is removed forming a pre-laminated receiver stock. An imaged receiver sheet, consisting of a representative image that has been formed with an incorrect orientation is laminated on a second thermoplastic layer and a second support layer; having a second support base, first aluminized layer and second release layer. The second support layer may be comprised of several layers or a single support base. An imageless receiver sheet consists of a third thermoplastic layer and a third support layer having a third support base, second aluminized layer and a third release layer. The third support layer may be comprised of several layers or a single support base. The representative image is encapsulated between the second thermoplastic layer and third thermoplastic layer and the second support layer is removed forming a laminated image receiver sheet with a corrected image orientation. The laminated image receiver sheet is laminated to the pre-laminated receiver stock and the third support layer is removed forming a pre-press proof with a correct image orientation.
A method of laminating a pre-press proof, whereby an imaged receiver sheet with an image having been written with an incorrect orientation is salvaged, which comprises the steps of laminating an imaged receiver sheet consisting of a representative image that has been formed with an incorrect orientation on a first thermoplastic layer and a first support layer; having a first support base, first aluminized layer and first release layer. It should be noted that the first support layer may be comprised of several layers or a single support base. An imageless receiver sheet consisting of a second thermoplastic layer and a second support layer having a second support base, second aluminized layer and a second release layer. The second support layer may be comprised of several layers or a single support base. The representative image is encapsulated between the first thermoplastic layer and the second thermoplastic layer and the first support layer is removed forming a laminated image receiver sheet with a corrected image orientation. The laminated image receiver sheet is laminated to a receiver stock and the second support layer is removed forming a pre-press proof with a correct image orientation.